I hope drivers will become conscious that they are being monitored from the sky and will hesitate to tailgate.

This lacks context

Not sure if monitoring from the sky is supposed to be in drivers' consciousness.

Well, they would not be conscious of the greater chance of maiming or death if they tailgate anyway, would they?

Monitoring works best if it is acted upon and reported, people caught and book thrown at them. That is what is going to get into people's consciousness.

Doesn't happen all the time in Japan though, not in comparison with say, separate speed cameras spread over distances on freeways catching cars with average speeds over the limits, as in New South Wales in Aus.

A pretty good little earner for the state government, that one.

If anyone tail-gates me, I slow down just to piss them off even more.

I found truck drivers are the worst, often tailgating at high speeds and although driving at 10 or 20 km/h over speed limit seems to be the norm here, trucks are even faster than that.

Dash cams point the wrong way, but supposing you had footage of someone tailgating with their number plate and the driver visible, would the police go after them and prosecute?

(No, didn't think so)

Don't helicopters cost a lot to keep in the air?